Fluxes play an important role in solder-joining electronic components, such as semiconductor devices, onto printed circuit cards and/or printed circuit boards (PCBs). The use of commonly available fluxes typically results in residues remaining on the soldered components. These residues, which can be difficult to remove, are undesirable as they often lead to short circuits and adhesional failure, for example, at the interface between the semiconductor device and, e.g., an underfill material. Thus, any residues that form should be easily and effectively removable, for example, using water or common cleaning solutions.
Further, many commonly available fluxes, such as those described in U.S. Pat. No. 5,615,827 issued to Arldt et al., cannot be employed in high throughput manufacturing. Namely, the nature of these flux compositions permits components to shift relative to each other when subject to the jostling and vibrations typically encountered during high throughput manufacturing. As a result, misalignment of components can occur.
Certain fluxes have been developed which have a “tackiness” property associated therewith, aimed at preventing such misalignments. However, these fluxes require the use of solvents, such as glycerol-ethoxylate, which undesirably remain liquid after reflow. This remaining liquid flux can further react with the solder, generating additional residues and corroding the solder. Further, the additional residues left by these fluxes cannot be removed with typical washing processes and therefore typically remain, causing short circuiting and delamination at the chip-underfill interface.
Therefore, flux compositions and techniques for the use thereof are needed for high throughput manufacturing, wherein a minimal amount of residue is produced and is easily removable using conventional washing techniques.